Improve the semantic of seq-some

Update seq-some to return non-nil if the predicate returns non-nil for
any element of the seq, in which case the returned value is the one
returned by the predicate.

* lisp/emacs-lisp/seq.el (seq-some): Update the function and its
  docstring.
* test/automated/seq-tests.el (test-seq-some): Add a regression test.
* doc/lispref/sequences.texi (Sequence Functions): Update the
  documentation for seq-some.

1 files changed, 4 insertions, 3 deletions

diff --git a/test/automated/seq-tests.el b/test/automated/seq-tests.el
index efbb90dd988..07a183d024e 100644
--- a/test/automated/seq-tests.el
+++ b/test/automated/seq-tests.el
@@ -131,11 +131,12 @@ Evaluate BODY for each created sequence.
 
 (ert-deftest test-seq-some ()
   (with-test-sequences (seq '(4 3 2 1))
-    (should (= (seq-some #'test-sequences-evenp seq) 4))
-    (should (= (seq-some #'test-sequences-oddp seq) 3))
+    (should (seq-some #'test-sequences-evenp seq))
+    (should (seq-some #'test-sequences-oddp seq))
     (should-not (seq-some (lambda (elt) (> elt 10)) seq)))
   (with-test-sequences (seq '())
-    (should-not (seq-some #'test-sequences-oddp seq))))
+    (should-not (seq-some #'test-sequences-oddp seq)))
+  (should (seq-some #'null '(1 nil 2))))
 
 (ert-deftest test-seq-contains ()
   (with-test-sequences (seq '(3 4 5 6))